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Technically called an aileron roll. https://en.wikipedia.org/wiki/Aileron_roll https://en.wikipedia.org/wiki/Aileron_roll

by cfj 11y ago

__rzzzwilson__ 11y ago
No, a barrel roll is different to an aileron roll. The wikipedia article linked to shows the difference. A barrel roll requires heading and altitude changes, an aileron roll should not.
- agumonkey 11y ago
  Yeah it's was confusing, an aileron roll wouldn't allow for this https://www.youtube.com/watch?v=pMWxuKcD6vE https://www.youtube.com/watch?v=pMWxuKcD6vE (posted above). Unless you rotate faster than gravity pulling the water down.
- cpncrunch 11y ago
  Yes, the are different. However what the OP is pointing out is that Tex actually did an aileron roll and not a barrel roll. (Watch the video and it's pretty obvious).
  - mikeash 11y ago
    I watched the video and it looks like a barrel roll to me. The airplane doesn't maintain altitude nor heading. Also that engineer who took a photo while kneeling next to a window would have been on the ceiling at that point if it had been an aileron roll.
    - cpncrunch 11y ago
      If you look at 1:56 on the AviationExplorer video you'll see there is little or no pitch change, so it couldn't be a barrel roll. I'm not sure how you can tell that it's heading is changing from that video. According to wikipedia "An aircraft performing an aileron roll will actually fly along a slightly helical path, and a very light, positive g force will be maintained" so the photographer wouldn't have been on the ceiling.
      - mikeash 11y ago
        I don't know which AviationExplorer video you're referring to, but there's supposedly only one video of the maneuver so I assume the one in the article is the same thing. I see quite a large pitch change there. The aircraft starts more or less level, then pulls up. While inverted it begins to move substantially nose down. As for heading, at the beginning of the video it's pointed well to the left, and at the end of the maneuver the fuselage is lined up with the camera. Wikipedia is confused or imprecise. Either that "positive g force" refers to the force on the aircraft relative to the Earth, or it's just wrong. Reading through the original reference that statement comes from, I believe it's the former. The book says: "...we have managed to substantially increase the angle of attack, to a point where the inverted wing is capable of maintaining altitude." If you're maintaining altitude while inverted, you're not pulling positive gees relative to the airplane, but you are pulling positive gees relative to the Earth. You can browse most of the chapter on aileron rolls in the book in question on Amazon: http://www.amazon.com/Basic-Aerobatics-Geza-Szurovy/dp/0070629269 http://www.amazon.com/Basic-Aerobatics-Geza-Szurovy/dp/00706...
        cpncrunch 11y ago
        https://www.youtube.com/watch?v=AaA7kPfC5Hk https://www.youtube.com/watch?v=AaA7kPfC5Hk See around 1:56. No significant heading or pitch changes that I can see, although it is difficult to tell because the camera is so far away.
dingaling 11y ago
Correct, a barrel roll requires 90 degree changes-of-course through the manouevre. Think of the seam-line on a toilet-roll tube; that's the path a barrel roll requires. Lots of pitch and roll, it is not a simple manoeuvre and has to be taught: https://www.youtube.com/watch?v=hASm6-2QLDU https://www.youtube.com/watch?v=hASm6-2QLDU To my knowledge no airliner has ever been barrel-rolled, it is a high-stress manoeuvre. Tex himself never claimed it was a barrel roll.
- userbinator 11y ago
  To my knowledge no airliner has ever been barrel-rolled, it is a high-stress manoeuvre. Tex himself never claimed it was a barrel roll. I think you've confused them; Tex says, quoted in the article, "The barrel roll is a one G maneuver and quite impressive, but the airplane never knows it’s inverted", while the aileron roll causes negative G at the "top" when the plane is inverted.
  - dingaling 11y ago
    Tex is incorrect or misquoted, a 1G barrel roll is next to impossible. More than 1G must generally be pulled at the entry point if you're even going to make the first loop. Even aerobatic champions in Su-26s struggle to do it, and those things have ridiculous power-to-weight. Furthermore, if you were watching a barrel roll you'd see the aeroplane's nose turn towards you as an observer. That'd didn't occur. What did Tex call it? The exact words out of his mouth: "So I came across and did a chandelle" https://www.youtube.com/watch?v=hASm6-2QLDU https://www.youtube.com/watch?v=hASm6-2QLDU Well, it certainly wasn't that as a chandelle is an FAA-certified check-manouevre involving a climbing turn. I know it's heresy to question 'national heroes' but frankly Tex didn't know what manouevre he did. All we know is he hacked something on the day, and it worked.
    - mannykannot 11y ago
      > Furthermore, if you were watching a barrel roll you'd see the aeroplane's nose turn towards you as an observer. That'd didn't occur. Not if the entry trajectory is away from you, as is the case in all the videos I have seen - were you thinking of Tex's description of it as a chandelle here? He uses the unqualified term 'roll' elsewhere in the interview, and the maneuver certainly qualifies, as the craft performed a 360-degree rotation around the longitudinal axis and finished on close to the entry heading. Movement of the camera to follow the aircraft may have concealed its barrel shape, but if you follow the fuselage orientation, you can see changes in heading consistent with a barrel roll, though possibly around an oval or pear-shaped barrel. Regardless of what you call it, I don't think the maneuver as filmed could be performed at nearly 1G. I wonder if what Hoover was trying to convey was 1) he didn't go negative G, and 2) he didn't pull any more Gs than a chandelle, which, as you say, is a standard check-maneuver (I do not know if the latter is true (with respect to G forces), though the entry into, and exit from, a barrel roll have some resemblances to a chandelle.)
InclinedPlane 11y ago
No. The 707 did an actual Barrel Roll, not an Aileron Roll.
- cpncrunch 11y ago
  No, definitely not a barrel roll. Watch the video and it's clearly obvious that it's not a barrel roll. Also, a barrel roll isn't a 1g maneouver.
  - mlonkibjuyhv 11y ago
    The only 1g maneuver that starts and ends with level flight is level flight.
mckoss 11y ago
An aileron roll will experience -1G - something you really don't want to do in an airliner. A barrel roll is specifically named because its like driving around the inside of a barrel; the plane always maintains positive Gs.

Technically called an aileron roll. https://en.wikipedia.org/wiki/Aileron_roll https://en.wikipedia.org/wiki/Aileron_roll

by cfj 11y ago

Technically called an aileron roll. https://en.wikipedia.org/wiki/Aileron_roll https://en.wikipedia.org/wiki/Aileron_roll

__rzzzwilson__ 11y ago

No, a barrel roll is different to an aileron roll. The wikipedia article linked to shows the difference. A barrel roll requires heading and altitude changes, an aileron roll should not.

agumonkey 11y ago
Yeah it's was confusing, an aileron roll wouldn't allow for this https://www.youtube.com/watch?v=pMWxuKcD6vE https://www.youtube.com/watch?v=pMWxuKcD6vE (posted above). Unless you rotate faster than gravity pulling the water down.
cpncrunch 11y ago
Yes, the are different. However what the OP is pointing out is that Tex actually did an aileron roll and not a barrel roll. (Watch the video and it's pretty obvious).
- mikeash 11y ago
  I watched the video and it looks like a barrel roll to me. The airplane doesn't maintain altitude nor heading. Also that engineer who took a photo while kneeling next to a window would have been on the ceiling at that point if it had been an aileron roll.
  - cpncrunch 11y ago
    If you look at 1:56 on the AviationExplorer video you'll see there is little or no pitch change, so it couldn't be a barrel roll. I'm not sure how you can tell that it's heading is changing from that video. According to wikipedia "An aircraft performing an aileron roll will actually fly along a slightly helical path, and a very light, positive g force will be maintained" so the photographer wouldn't have been on the ceiling.
    - mikeash 11y ago
      I don't know which AviationExplorer video you're referring to, but there's supposedly only one video of the maneuver so I assume the one in the article is the same thing. I see quite a large pitch change there. The aircraft starts more or less level, then pulls up. While inverted it begins to move substantially nose down. As for heading, at the beginning of the video it's pointed well to the left, and at the end of the maneuver the fuselage is lined up with the camera. Wikipedia is confused or imprecise. Either that "positive g force" refers to the force on the aircraft relative to the Earth, or it's just wrong. Reading through the original reference that statement comes from, I believe it's the former. The book says: "...we have managed to substantially increase the angle of attack, to a point where the inverted wing is capable of maintaining altitude." If you're maintaining altitude while inverted, you're not pulling positive gees relative to the airplane, but you are pulling positive gees relative to the Earth. You can browse most of the chapter on aileron rolls in the book in question on Amazon: http://www.amazon.com/Basic-Aerobatics-Geza-Szurovy/dp/0070629269 http://www.amazon.com/Basic-Aerobatics-Geza-Szurovy/dp/00706...
      - cpncrunch 11y ago
        https://www.youtube.com/watch?v=AaA7kPfC5Hk https://www.youtube.com/watch?v=AaA7kPfC5Hk See around 1:56. No significant heading or pitch changes that I can see, although it is difficult to tell because the camera is so far away.

dingaling 11y ago

Correct, a barrel roll requires 90 degree changes-of-course through the manouevre. Think of the seam-line on a toilet-roll tube; that's the path a barrel roll requires. Lots of pitch and roll, it is not a simple manoeuvre and has to be taught: https://www.youtube.com/watch?v=hASm6-2QLDU https://www.youtube.com/watch?v=hASm6-2QLDU To my knowledge no airliner has ever been barrel-rolled, it is a high-stress manoeuvre. Tex himself never claimed it was a barrel roll.

userbinator 11y ago
To my knowledge no airliner has ever been barrel-rolled, it is a high-stress manoeuvre. Tex himself never claimed it was a barrel roll. I think you've confused them; Tex says, quoted in the article, "The barrel roll is a one G maneuver and quite impressive, but the airplane never knows it’s inverted", while the aileron roll causes negative G at the "top" when the plane is inverted.
- dingaling 11y ago
  Tex is incorrect or misquoted, a 1G barrel roll is next to impossible. More than 1G must generally be pulled at the entry point if you're even going to make the first loop. Even aerobatic champions in Su-26s struggle to do it, and those things have ridiculous power-to-weight. Furthermore, if you were watching a barrel roll you'd see the aeroplane's nose turn towards you as an observer. That'd didn't occur. What did Tex call it? The exact words out of his mouth: "So I came across and did a chandelle" https://www.youtube.com/watch?v=hASm6-2QLDU https://www.youtube.com/watch?v=hASm6-2QLDU Well, it certainly wasn't that as a chandelle is an FAA-certified check-manouevre involving a climbing turn. I know it's heresy to question 'national heroes' but frankly Tex didn't know what manouevre he did. All we know is he hacked something on the day, and it worked.
  - mannykannot 11y ago
    > Furthermore, if you were watching a barrel roll you'd see the aeroplane's nose turn towards you as an observer. That'd didn't occur. Not if the entry trajectory is away from you, as is the case in all the videos I have seen - were you thinking of Tex's description of it as a chandelle here? He uses the unqualified term 'roll' elsewhere in the interview, and the maneuver certainly qualifies, as the craft performed a 360-degree rotation around the longitudinal axis and finished on close to the entry heading. Movement of the camera to follow the aircraft may have concealed its barrel shape, but if you follow the fuselage orientation, you can see changes in heading consistent with a barrel roll, though possibly around an oval or pear-shaped barrel. Regardless of what you call it, I don't think the maneuver as filmed could be performed at nearly 1G. I wonder if what Hoover was trying to convey was 1) he didn't go negative G, and 2) he didn't pull any more Gs than a chandelle, which, as you say, is a standard check-maneuver (I do not know if the latter is true (with respect to G forces), though the entry into, and exit from, a barrel roll have some resemblances to a chandelle.)

InclinedPlane 11y ago

No. The 707 did an actual Barrel Roll, not an Aileron Roll.

cpncrunch 11y ago
No, definitely not a barrel roll. Watch the video and it's clearly obvious that it's not a barrel roll. Also, a barrel roll isn't a 1g maneouver.
- mlonkibjuyhv 11y ago
  The only 1g maneuver that starts and ends with level flight is level flight.

mckoss 11y ago

An aileron roll will experience -1G - something you really don't want to do in an airliner. A barrel roll is specifically named because its like driving around the inside of a barrel; the plane always maintains positive Gs.